Exhaust Gas Purification Apparatus for Engine

ABSTRACT

An exhaust gas purification apparatus for an engine includes an exhaust gas bypass connected to the engine, a muffler connected to the exhaust gas bypass, and a catalytic carrier. The muffler defines an outlet communicating with the atmosphere. The catalytic carrier defines a through-hole for receiving catalyst. The catalytic carrier is mounted in the muffler, and at the outlet of the muffler. The through-hole of the catalytic carrier communicates with the atmosphere via the outlet.

BACKGROUND OF THE INVENTION

The present invention relates to purification apparatuses, and particularly to an exhaust gas purification apparatus for an engine.

Exhaust gas purification apparatus for a gasoline engine has been proposed, which oxidize or reduce hazardous substances (carbon monoxide CO, hydrocarbons HC, nitrogen oxides NOx, and so forth) exhausted from the engine, and consequently, change hazardous substances into more harmless substances (carbon dioxide CO₂, and water H₂O).

A typical exhaust gas purification apparatus for an engine includes an exhaust gas bypass connected to the engine, a muffler connected to the exhaust gas bypass, and a catalytic carrier mounted to the exhaust gas bypass or the muffler. Catalyst including Palladium (Pd), Platinum (Pt) or Rhodium (Rh) is received in the catalytic carrier. An air-guiding device absorbs air into the catalytic carrier. The air oxidizes the hazardous substances via the catalyst to change the hazardous substances into harmless substances. However, the air-guiding device is mounted to the exhaust gas bypass, which leads to a high cost. Meanwhile, an additional space is needed for the exhaust gas bypass to accommodate the air-guiding device.

For another typical engine, such as an engine having a little exhaust gas capacity, there is not an exhaust gas bypass connected to the engine. Thus, there is not additional space for receiving an air-guiding device. A catalytic carrier is mounted to a muffler of the engine. Hazardous substances from the engine cannot easily be changed into harmless substances because a high temperature or lack of oxides. Thus, mass of hazardous substances will be let off to pollute the atmosphere.

What is needed is to provide an exhaust gas purification apparatus for an engine.

SUMMARY

An exemplary exhaust gas purification apparatus for an engine includes an exhaust gas bypass connected to the engine, a muffler connected to the exhaust gas bypass, and a catalytic carrier. The muffler defines an outlet communicating with the atmosphere. The catalytic carrier defines a through-hole for receiving catalyst. The catalytic carrier is mounted in the muffler, and at the outlet of the muffler. The through-hole of the catalytic carrier communicates with the atmosphere via the outlet.

Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sketch view of an exhaust gas purification apparatus in accordance with a preferred embodiment of the present invention;

FIG. 2 is a cutaway view of FIG. 1, showing a catalytic carrier mounted to a muffler;

FIG. 3 a cutaway view of an exhaust gas purification apparatus in accordance with a second preferred embodiment of the present invention; and

FIG. 4 is a cutaway view of an exhaust gas purification apparatus in accordance with a third preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2, an exhaust gas purification apparatus in accordance with a preferred embodiment of the present invention is shown for purify hazardous substances from an engine 1. The exhaust gas purification apparatus includes an exhaust gas bypass 11 connected to the engine 1, a muffler 2 connected to the exhaust gas bypass 11, and a catalytic carrier 3 containing catalyst, such as Pd, Pt, or Rh.

The muffler 2 defines a muffling room 21, an inlet 22, and an outlet 23. The inlet 22 and the outlet 23 communicate the muffling room 21, respectively. The muffler 2 is connected to the exhaust gas bypass via the inlet 22. The outlet 23 communicates with the atmosphere.

The catalytic carrier 3 includes a metal cylinder. The metal cylinder contains the catalyst. The catalytic carrier 3 is located at the outlet 23 of the muffler 2. A through-hole 21 is defined in the catalytic carrier 3, for communicating with the atmosphere and the muffling room 21.

When the engine 1 works, exhaust gas generated by the engine 1 passes in turn through the exhaust gas bypass 11, the inlet 22 of the muffler 2, the muffling room 21, the through-hole 31 of the catalytic carrier 3, and the outlet 23 of the muffler 2, then into the atmosphere. The engine 1 generates a discontinuous negative pressure when working. The outlet 23 of the muffler 2 also generates a discontinuous negative pressure when letting off the exhaust gases. Air containing oxides are absorbed into the catalytic carrier 3 through the outlet 23 of the muffler 2 via the negative pressure. The air oxidizes the exhaust gas into harmless substance via the catalyst.

FIG. 3 shows an exhaust gas purification apparatus in accordance with a second preferred embodiment of the present invention. A pipe 4 having an L shape is located in the muffling room 21 of the muffler 2, with an end at the outlet 23 of the muffler 2. The catalytic carrier 3 is located in the pipe 4 at the end adjacent the outlet 23. Different negative pressures at the outlet 23 of the muffler 2 can be obtained by changing a length or diameter of the pipe 4.

FIG. 4 shows an exhaust gas purification apparatus in accordance with a third preferred embodiment of the present invention. A separating board 5 is located in a middle portion of the muffler 2, and between the inlet 22, and outlet 23. The muffling room 21 is divided into a front muffling room 211, and a rear muffling room 212. An opening 51 is defined in the separating board 5.

It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention. 

1. An exhaust gas purification apparatus for an engine, comprising: an exhaust gas bypass for being connected to the engine; a muffler connected to the exhaust gas bypass, the muffler defining an outlet communicating with the atmosphere; and a catalytic carrier defining a through-hole for receiving catalyst, the catalytic carrier mounted in the muffler, and at the outlet of the muffler, the through-hole communicating with the atmosphere via the outlet.
 2. The exhaust gas purification apparatus as claimed in claim 1, wherein the muffler further defines a muffling room, for receiving the catalytic carrier, the outlet of the muffler communicating with the muffling room.
 3. The exhaust gas purification apparatus as claimed in claim 2, wherein the muffler still further defines an inlet communicating with the muffling room, the muffler is connected to the exhaust gas bypass via the inlet.
 4. The exhaust gas purification apparatus as claimed in claim 2, wherein a pipe is located in the muffling room of the muffler, with an end thereof at the outlet of the muffler, the catalytic carrier is located in the pipe and at the end of the pipe adjacent the outlet.
 5. The exhaust gas purification apparatus as claimed in claim 2, wherein a separating board is located in the muffling room of the muffler, the muffling room is divided into a front muffling room, and a rear muffling room, the catalytic carrier is located in the rear muffling room, an opening is defined in the separating board.
 6. An exhaust gas purification system, comprising: an engine; an exhaust gas bypass connected to the engine; a muffler connected to the exhaust gas bypass, the muffler defining an outlet communicating with the atmosphere; and a catalytic carrier defining a through-hole for receiving catalyst, the catalytic carrier mounted in the muffler, and at the outlet of the muffler, the through-hole communicating with the atmosphere via the outlet.
 7. The system as claimed in claim 6, wherein the muffler further defines a muffling room, for receiving the catalytic carrier, the outlet of the muffler communicating with the muffling room.
 8. The system as claimed in claim 7, wherein the muffler still further defines an inlet communicating with the muffling room, the muffler is connected to the exhaust gas bypass via the inlet.
 9. The system as claimed in claim 7, wherein a pipe is located in the muffling room of the muffler, with an end thereof at the outlet of the muffler, the catalytic carrier is located in the pipe and at the end of the pipe adjacent the outlet.
 10. The system as claimed in claim 7, wherein a separating board is located in the muffling room of the muffler, the muffling room is divided into a front muffling room, and a rear muffling room, the catalytic carrier is located in the rear muffling room, an opening is defined in the separating board.
 11. The system as claimed in claim 6, wherein the engine generates a first discontinuous negative pressure when working.
 12. The system as claimed in claim 11, wherein the outlet generates a second discontinuous negative pressure when letting off exhaust gases. 